The day after Ronald Herrera made an emergency start at Triple-A, Brian Cashman told me to “keep an eye on him, we think he has a chance.”

On the surface, it seemed strange. Herrera had just given up five runs in five innings. But the Yankees GM noted the eight strikeouts and, more vitally, that he was only 20 years old and was going to be sent back to the more age-appropriate Double-A.

Even with his 21st birthday approaching next week, Herrera is the youngest pitcher in the Eastern League, and on Tuesday he threw eight no-hit innings for Trenton against New Hampshire as part of a joint no-hitter.

The Fisher Cats are viewed as a poor offensive team. On Wednesday, Trenton lefty Dietrich Enns no-hit them for 5 1/3 innings and threw seven shutout innings in all to go to 23 2-3 innings this year without allowing a run. But Enns turns 25 in three weeks and is more of a finesse type.

Herrera’s age/skill combo has made him more exciting to the Yankees, who acquired the righty from the Padres in the offseason for Jose Pirela, who was demoted to the minors earlier this week by San Diego. This was part of the Yankees’ offseason effort to add starting pitching to the barren upper levels of their minor league system.

And it is not just the Yankees who appreciate him. This is from an opposing scout: “He is a medium-body right-hander who looks generic as hell. The stuff is not overpowering, but the pitchability and command are both so good. He is so poised, especially for his age. I love his makeup. I love how he mixes pitches. He is a big-league starting pitcher.”

Two Mets have special OPS

Through Tuesday, Michael Conforto (1.061) and Yoenis Cespedes (1.056) ranked seventh and eighth in OPS in the majors among players qualified for the batting title (seven of the top eight were NL players, and Daniel Murphy was third at 1.103).

It is early, of course. But the team record is 1.012 by Mike Piazza in 2000, the only time in Mets history a player has been over 1.000 (John Olerud was at .998 in 1998).

That 2000 season was the closest the Mets ever came to having two players reach 1.000 with Edgardo Alfonzo at .967. No major league team has had two players at an 1.000 OPS or more since 2006, when David Ortiz and Manny Ramirez did it for the Red Sox and the White Sox had Jermaine Dye and Jim Thome.